BILL O'REILLY, HOST: In the "Back of the Book" segment, with the rise in cable TV and the Internet, demonstrations of teenage sexuality are all over the place, as you know, especially for girls. Young women icons Britney Spears and Paris Hilton openly flaunt their, well, charms and millions of young girls see it.

With us now, Dr. Sari Locker. She teaches adolescent psychology at Columbia University. She's also author of the book, "The Complete Idiot's Guide to Amazing Sex".

Now I want to define this conversation. I don't care what anybody over 18 does. I'm a libertarian in that regard. OK? I don't make judgments about people's behavior once they reach the age of 18. They can do whatever they want as long as they don't break the law. OK? That's up to them.

But girls 11 to 16 are now under siege by their role models, Miss Spears, Miss Hilton, all of the other people, acting inappropriately. And the Internet, MySpace, this crazy, crazy stuff that they see.

How concerned should parents be? Or is this a natural thing?

SARI LOCKER, AUTHOR, "COMPLETE IDIOT'S GUIDE TO AMAZING SEX": It's natural, and it's normal for adolescents to be striving for their independence and trying to search for their identity. And they are going to latch onto some pop cultural role models. That's why parents need to be concerned.

O'REILLY: The parents should be concerned?

LOCKER: Yes. The natural, normal part of it that adolescents are experiencing their sexually for the first time in their lives. And they want to be demonstrating how that feels. But the dangerous part of it is if your children are following these, well, disgusting role models, then you need to rein them in...

O'REILLY: ...So you feel that these are disgusting role models?

LOCKER: Absolutely.

O'REILLY: Why?

LOCKER: They're acting in ways that go far beyond what people did in previous decades. So a lot of people want to say this is no different than the '60s, when some girls would flash at Woodstock, or even in the '80s, when teenagers were trying to dress like Madonna.

But it's entirely different, because the behavior today is really pornographic. It's young women, these pop celebrities -- without underpants? Showing their genitals? And it's Janet Jackson flashing her breasts. And you know, that's already a couple years old.

But somehow, just when that image started to leave my mind, the image of Britney without panties entered and for teenage girls it's much worse.

O'REILLY: Well, what happens to a 12-year-old who sees what you just mentioned, these displays? How do they process that?

LOCKER: They don't know how to process it. And that's why the parents need to help them and to use it as a moment to teach them and to say, "What you just saw is not appropriate behavior." They need to give them those values.

O'REILLY: And that's good for most people, but there are lot of girls who don't have responsible parents, and this is the argument with rap music, as well.

Now, when a girl dresses inappropriately, in the sense that she's 14 and she wants the low cuts and high skirts and this and that, as a parent, do you just say no? What do you do?

LOCKER: You say, No. And you tell them what the consequences are going to be if they disobey your rules. I mean, the best parenting style for teenagers is an authoritative parent, a parent who the teens can talk to. So you want to leave the dialogue open.

O'REILLY: OK, you tell them no and here's the reason why? But what's the reason why? What do you tell them?

LOCKER: The reason why is that people are not bright enough to distinguish between what someone looks like and what someone's personality is. So when somebody dresses slutty, everyone's going to think they're slutty.

You know when Britney...

O'REILLY: But they're going to say, "Well, all my friend dress like that."

LOCKER: Well, you can tell them, you know, when Britney and Paris and Lindsay Lohan went out and they're all out partying, they called that "the bimbo summit." You can say to your child, do you want to be part of "the bimbo summit"?

O'REILLY: But what if they want to be bimbos?

LOCKER: Well, then you can tell them about the consequences for their future. We all need to be focusing on developing healthy teenagers who care about their future aspirations.

O'REILLY: Yes.

LOCKER: Not teenagers who care about...

O'REILLY: It's hard, though. The peer pressure is enormous.

My last question is why do women, young women do this stuff: flash and go to New Orleans and do the crazy thing? Why do they do it? Do they just want attention? Is that what it's all about?

LOCKER: A lot of attention, and a lot of it, Bill, I have to say, we're contributing to this. Because how many times in the last hour did you show the segments of the girls flashing? And how many times during this segment when I was discussing it do we have to show those images again?

O'REILLY: So we have to show the audience what happens. See, a lot of people never see this.

LOCKER: But it's -- well, I don't know. They see it all day log. They see it from the morning news, the nighttime news.

O'REILLY: Trust me. Well, OK. But they don't see it like that.

Doctor, interesting. Thank you very much.

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